Middle ear infection (Otitis Media or OM) is the most common infection in young children in the western world. It is estimated that about 30% of antibiotics prescribed in the United States is used to treat otitis media in children. This widespread use of antibiotics has significant consequences arising from the development of resistant microorganisms. Otitis Media is the most common reason for parents to be absent from work to take care of their children, with a cost to the economy of several billion dollars annually.
In the region of the infection, liquid exudate is formed due to inflammation of the middle ear as the result of the infection. This liquid or fluid can occupy a portion of the middle ear and in some cases can fill the entire middle ear cavity creating local high pressure. The secreted liquid in the middle ear cannot drain through the Eustachian tube because the Eustachian tube becomes blocked due to swelling of the adenoids and adjacent tissues. Accumulation of fluid in middle ear is associated with a high level of discomfort and pain, and is often associated with loss of balance in young children.
Typically the first approach to treating Otitis Media is systemic antibiotics. If the antibiotic treatment is not successful and if infection recurred more frequently, the standard of care intervention is myringotomy with tube placement, in which a tympanostomy tube (TT) is placed through the eardrum (tympanic membrane), normally under complete anesthesia. A tympanostomy tube allows fluid to drain out of middle ear and functions to ventilate and equalize the pressure with the outside atmosphere. Because of these functions, tympanostomy tubes are often referred to as vent tubes or simply ear tubes. The standard of care in the United States is to prescribe antibiotic otic drops after myringotomy. The most commonly prescription includes the antibiotic ciprofloxacin and the anti-inflammatory compound dexamethasone. The most recognized otic drops prescription in United States is Ciprodex® made by Alcon Laboratories. Ciprofloxacin in Ciprodex is a 0.3% suspension of the hydrochloride salt, which has a high solubility in water. Otic drops are typically administered with the patient lying on his or her side with the infected ear facing upward, so that the liquid of the administered ear drops descends by gravity and assisted by pumping action through the tympanostomy tube into the middle ear.
Otitis media is the leading cause of acquired hearing loss in the pediatric population, and is also the most common reason an ill child under age 15 visits a pediatrician or emergency room, with 24.5 million office visits in 1990 alone. The cost of diagnosing and treating Otitis Media exceeds $5 billion annually in the United States. Otitis Media is a disease that disproportionately affects minority populations, especially Native American children, who have three times the incidence of Otitis Media as whites. Otitis Media prevalence is also significantly higher with children in daycare, who receive a tympanostomy tube placement at many times the rate of young children who do not attend daycare. Otitis Media has consequences for women in the workforce as well, since women typically remain the primary caregivers for these children, and they are often responsible for obtaining medical care. An average of one half of a workday is required for each physician visit for each Otitis Media episode. This has significant national economic consequences given that women currently make up 46% of the American workforce.
Hearing loss is the most common complication of Otitis Media, often causing moderate to severe impairment. Multiple studies have indicated that children affected by Otitis Media-related hearing loss have cognitive impairment, language skill deficits, poor school performance, and antisocial behavior. Repeated episodes of Otitis Media may lead to permanent forms of hearing loss through tympanic membrane perforation, tympanosclerosis development, ossicular disruption, and irreversible middle ear mucosal injury. In addition, chronic serious Otitis Media complicates 10% of all acute Otitis Media episodes despite appropriate medical therapy, resulting in persistent effusion and associated hearing loss.
The clinical problem of Otitis Media in its various forms thus continues to present an enormous public health challenge. Myringotomy with tympanostomy tube placement is the most effective treatment for these patients, and is the most commonly performed surgical procedure in children. In chronic otitis media with effusion (OME), tympanostomy tubes facilitate removal of persistent middle ear effusion with suction. In recurrent acute Otitis Media, tympanostomy tubes have been shown to reduce the duration, severity, and incidence of acute Otitis Media episodes. Even when an Otitis Media episode does develop, treatment options in patients with tympanostomy tubes are superior since ototopical rather than systemic antimicrobial medications may be deployed. The most common ototopical prescription includes the antibiotic ciprofloxacin and the anti-inflammatory compound dexamethasone, Ciprodex® made by Alcon Laboratories. Ciprofloxacin in Ciprodex is a 0.3% suspension of the hydrochloride salt which has a high solubility in water. Ototopical drops are typically administered with the patient lying on his or her side with the infected ear facing upward, so that the liquid of the administered ear drops descends by gravity and assisted by pumping action through the tympanostomy tube into the middle ear.
Despite the generally successful use of tympanostomy tubes in treating Otitis Media, there remain noteworthy problems in a significant percentage of children undergoing this procedure. The most common complication after tympanostomy tube placement is otorrhea, with one recent study indicating an incidence of 75% within the first post-operative year. Although most of these episodes can be effectively treated with conservative management, primarily through the targeted application of topical antibiotics, in aggregate they still represent a significant morbidity.
Even more problematic and burdensome are those patients who develop not isolated but chronic post-tympanostomy tube otorrhea (PTTO). Chronic PTTO, defined as purulent drainage lasting longer than 6 weeks despite treatment and without the presence of cholesteatoma, complicates 2-5% of all tympanostomy tube placements. The treatment of chronic PTTO remains a difficult therapeutic challenge. Systemic oral antibiotics and frequent aural toilet of the affected ear are generally recommended as initial therapy, but many patients require the use of long-term intravenous antibiotics, which itself has a 20% short-term failure rate and substantially higher recidivism over the longer term. These recalcitrant patients may ultimately require aggressive surgical intervention, typically tympanomastoidectomy.
These considerations highlight the continued difficulties of dealing with the very common problem of otitis media and its complications. Improved devices and methods would represent a highly significant advance in otolaryngology, and would have a dramatic impact on public health especially young children.